1. Field of the present
The present invention relates to artificial marble which has superior impact resistance and thermal shock resistance, moreover is superior in formation cracking characteristics and heat resistance, and is formed by polymerization within a mold.
2. Related Art
In general, unsaturated polyester resins are produced by means of the production of an unsaturated polyester by means of the heat esterification of an unsaturated dibasic acid such as maleic acid anhydride, fumaric acid, itaconic acid or the like, or a mixture of such an unsaturated dibasic acid with a saturated dibasic acid such as phthalic acid anhydride, isophthalic acid, terephthalic acid, or the like, and by reaction with a glycol such as ethylene glycol, propylene glycol or the like, and the dissolving of the resulting unsaturated polyester with a polymerizable monomer such as styrene, vinyl toluene, diallyl phthalate, acrylic acid ester, methacrylic acid ester, and the like. Artificial marble is generally obtained by means of the polymerization curing in a mold of a compound consisting of this unsaturated polyester resin composition, a filler, and a curing catalyst. In order to improve the artificial marble by adding impact resistance and thermal shock resistance, saturated dibasic acids having a long straight main chain, such as adipic acid and sebacic acid, were conventionally used as the raw material for the unsaturated polyester, and glycols having a straight main chain, such as diethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, 1,6-hexanediol, and the like, were used in an attempt to provide softness and flexibility characteristics.
However, when these raw materials were used, the water resistance of the cured resin was remarkably reduced, the artificial marble had inferior thermal shock resistance, and cracking occurred. Furthermore, artificial marble which did not possess gel coating on the surface layer thereof exhibited poor chemical resistance, and in addition the surface quality thereof was poor.